package com.zxlfysj.tree.threadedbinarytree;

/**
 * 线索化二叉树
 * @author yangshujing
 * @create 2020-08-19 21:04
 */
public class ThreadedBinaryTreeDemo {
    public static void main(String[] args) {
        //测试中序线索化二叉树
         HeroNode root = new HeroNode(1, "tom");
         HeroNode node2 = new HeroNode(3, "jack");
         HeroNode node3 = new HeroNode(6, "smith");
         HeroNode node4 = new HeroNode(8, "mary");
         HeroNode node5 = new HeroNode(10, "king");
         HeroNode node6 = new HeroNode(14, "lucy");
         root.setLeft(node2);
         root.setRight(node3);
         node2.setLeft(node4);
         node2.setRight(node5);
         node3.setLeft(node6);
        ThreadedBinaryTree threadedBinaryTree = new ThreadedBinaryTree();
        threadedBinaryTree.setRoot(root);
        threadedBinaryTree.infixThreadedNodes(root);
        System.out.println(node5.getRight());
        System.out.println("*******");
        //线索化的方式遍历线索化二叉树
        threadedBinaryTree.threadedList();


    }
}

//定义线索化二叉树
class ThreadedBinaryTree {
    private HeroNode root;

    private HeroNode pre = null; //线索化时，指向前一个节点的指针

    public void setRoot(HeroNode root) {
        this.root = root;
    }


    //遍历线索化二叉树(已中序线索化)
    public void threadedList() {
        HeroNode node = root;
        while(node != null) {
            //循环找到leftType == 1的结点
            //leftType == 1 ，说明结点有线索化
            while(node.getLeftType() == 0) {
                node = node.getLeft();
            }
            System.out.println(node);
            while(node.getRightType() == 1) {
                node = node.getRight();
                System.out.println(node);
            }
            node = node.getRight();

        }
    }


    /**
     * 中序线索化
     * @param node  当前需要线索化的节点
     */
    public void infixThreadedNodes(HeroNode node) {
        if(node == null) {
            return;
        }
        //线索化左子树
        infixThreadedNodes(node.getLeft());

        //处理当前节点的前驱结点
        if(node.getLeft() == null) {
            node.setLeft(pre);
            node.setLeftType(1);
        }
        //处理后继结点
        if(pre != null &&pre.getRight() == null) {
            pre.setRight(node);
            pre.setRightType(1);
        }
        //每处理一个结点后，让当前节点是下一个结点的前驱结点，
        // 为了下一次递归时处理线索化上一个结点的后继结点
        pre = node;

        //线索化右子树
        infixThreadedNodes(node.getRight());
    }

    //删除节点
    public void delNode(int no) {
        if(root != null) {
            if(root.getNo() == no) {
                root = null;
                return;
            } else {
                root.delNode(no);
            }
        } else{
            System.out.println("这是颗空树");
            return;
        }
    }

    //前序遍历
    public void preOrder() {
        if (this.root != null) {
            this.root.preOrder();
        } else {
            System.out.println("二叉树为空");
        }
    }

    //中序遍历
    public void infixOrder() {
        if (this.root != null) {
            this.root.infixOrder();
        } else {
            System.out.println("二叉树为空");
        }
    }

    //后序遍历
    public void postOrder() {
        if (this.root != null) {
            this.root.postOrder();
        } else {
            System.out.println("二叉树为空");
        }
    }

    //前序遍历查找
    public HeroNode preOrderSearch(int no) {
        if (this.root != null) {
            return this.root.preOrderSearch(no);
        } else {
            System.out.println("二叉树为空");
            return null;
        }
    }

    //中序遍历查找
    public HeroNode infixOrderSearch(int no) {
        if (this.root != null) {
            return this.root.infixOrderSearch(no);
        } else {
            System.out.println("二叉树为空");
            return null;
        }
    }

    //后序遍历查找
    public HeroNode postOrderSearch(int no) {
        if (this.root != null) {
            return this.root.postOrderSearch(no);
        } else {
            System.out.println("二叉树为空");
            return null;
        }
    }
}

class HeroNode {
    private int no;
    private String name;
    private HeroNode left;
    private HeroNode right;

    private int leftType; //0表示指向左子树，1表示指向前驱结点
    private int rightType; //0表示指向右子树，1表示指向后继结点

    public int getLeftType() {
        return leftType;
    }

    public void setLeftType(int leftType) {
        this.leftType = leftType;
    }

    public int getRightType() {
        return rightType;
    }

    public void setRightType(int rightType) {
        this.rightType = rightType;
    }

    public HeroNode(int no, String name) {
        this.no = no;
        this.name = name;
    }

    public int getNo() {
        return no;
    }

    public void setNo(int no) {
        this.no = no;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public HeroNode getLeft() {
        return left;
    }

    public void setLeft(HeroNode left) {
        this.left = left;
    }

    public HeroNode getRight() {
        return right;
    }

    public void setRight(HeroNode right) {
        this.right = right;
    }

    @Override
    public String toString() {
        return "HeroNode{" +
                "no=" + no +
                ", name='" + name + '\'' +
                '}';
    }

    //递归删除结点
    //1、如果删除的是叶子结点，则删除此节点
    //2、如果删除的是非叶子结点，则删除该子树
    public void delNode(int no) {
        if( this.left != null &&this.left.no == no) {
            this.left = null;
            return;
        }
        if( this.right != null &&this.right.no == no) {
            this.right = null;
            return;
        }
        //向左子树递归删除
        if(this.left != null) {
            this.left.delNode(no);
        }
        //向右子树递归删除
        if(this.right != null) {
            this.right.delNode(no);
        }

    }

    //前序遍历
    public void preOrder() {
        System.out.println(this); //输出父节点
        //向左子树递归前序遍历
        if (this.left != null) {
            this.left.preOrder();
        }
        //向右子树递归前序遍历
        if (this.right != null) {
            this.right.preOrder();
        }
    }

    //中序遍历
    public void infixOrder() {
        //向左子树递归中序遍历
        if (this.left != null) {
            this.left.infixOrder();
        }
        //输出父节点
        System.out.println(this);
        //向右子树递归中序遍历
        if (this.right != null) {
            this.right.infixOrder();
        }

    }

    //后序遍历
    public void postOrder() {
        //向左子树递归后序遍历
        if (this.left != null) {
            this.left.postOrder();
        }
        //向右子树递归后序遍历
        if (this.right != null) {
            this.right.postOrder();
        }
        //输出父节点
        System.out.println(this);
    }

    //前序遍历查找
    public HeroNode preOrderSearch(int no) {
        //比较父节点
        if (this.no == no) {
            return this;
        }
        HeroNode resNode = null;
        //向左子树递归查找
        if (this.left != null) {
            resNode = this.left.preOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //向右子树递归查找
        if (this.right != null) {
            resNode = this.right.preOrderSearch(no);
        }
        return resNode;

    }

    //中序遍历查找
    public HeroNode infixOrderSearch(int no) {
        HeroNode resNode = null;
        //向左子树递归查找
        if (this.left != null) {
            resNode = this.left.infixOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //比较父节点
        if (this.no == no) {
            resNode = this;
        }
        //向右子树递归查找
        if (this.right != null) {
            resNode = this.right.infixOrderSearch(no);
        }
        return resNode;

    }

    //后序遍历查找
    public HeroNode postOrderSearch(int no) {
        HeroNode resNode = null;
        //向左子树递归查找
        if (this.left != null) {
            resNode = this.left.postOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //向右子树递归查找
        if (this.right != null) {
            resNode = this.right.postOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //比较父节点
        if (this.no == no) {
            resNode = this;
        }
        return resNode;
    }
}
